This is a national stage application based on and claiming priority from, PCT/FI 99/00084, filed on Feb. 05, 1999 which in turn claims priority from Finnish Application 980268 filed on Feb. 6, 1998.
1. Field of the Invention
The present invention relates to new cyclic olefins. In particular, the invention concerns a process for producing unsaturated cyclic compounds from terpenes. Further, the invention concerns polymers comprising repeating units of the new cyclic olefins.
2. Description of Related Art
Cyclic Olefin Copolymers, COC, are polymeric materials of high interest. They are particularly attractive because their properties can easily be varied and the materials be used in various articles ranging from elastomers to High Perfomance Engineering Plastics. A further advantage of these materials is that they can be made using existing polyethylene or polypropylene polymerization reactors.
The COC""s are commercially prepared by copolymerizing, cyclic monomers, such as norbornene or substituted norbornenes, with olefinic comonomers, in particular lower alkenes or styrene. The copolymerization reactions are typically carried out in the presence of catalysts. Thus, tetracyclododecene is copolymerized with ethylene using vanadium-type Ziegler-Natta catalysts (Mitsui Chemical""s APEL). Metallocene catalysts have been also used for the copolymerization of norbornene with ethylene (commercially available products are Mitsui Chemical""s APO and Ticona""s TOPAS). Soft elastomeric types of polyolefins are obtained by Idemitsu Kosan by copolymerization of small amounts of norbornene with ethylene. Furthermore, the use of metallocenes for homopolymerization of norbornene as well as for catalytic copolymerization of substituted norbornenes with ethylene, propylene and styrene is known in the art. Other Single Site Catalysts, like palladium and nickel catalysts, have been used in homo- and copolymerization of norbornene and substituted norbornenes. Engineering types of COC are made by ring-opening methathesis polymerization (ROMP) of substituted norbornenes (commercially available products are represented by BF Goodrich""s TELENE OP, Nippon Zeon""s ZEONEX and Japan Synthetic Rubber""s ARTON). The ROMP-technique can also be employed from manufacturing elastomers (Hxc3xcls"" VESTENAMER polycyclooctene and Atochem""s NORSOREX polynorbornene) as well as RIM thermosets (BF Goodrich""s TELENE RIM).
The future of the COC-polymers depends, however, to a high degree on the availability and price of the cyclic monomers. All the cyclic monomers used in the art and presented above are made from raw-materials obtainable from the petrochemical industry and originating in a non-renewable source, i.e. oil. Norbornene and tetracyclododecene are made from dicyclopentadiene and ethylene both of which come from the ethylene cracker. The reaction is carried out by subjecting the feed to a Diels-Alder process which is hazardous. There is only one producer (Atochem) of norbornene and tetracyclododecene in the world and a capacity increase is very unlikely.
In the above cases mixtures of endo- and exo-diastereomers are obtained and the exo/endo ratio has significant effects on the polymerlzation processes and the technical properties of the polymers.
Alternatives to norbornene and tetracyclododecene are urgently needed due to technical reasons as well as the supply situation.
It is an object of the present invention to eliminate the problems of the prior art and to provide a process for synthesizing novel cyclic oletins which can be used as monomers for production of polymers by homo- or copolymerization.
It is another object of the present invention to provide a polymer comprising cyclic olefin units according to the present invention.
It is a further object of the present invention to provide new monomeric compounds.
These and other objects, together with the advantages thereof over known processes, which shall become apparent from the specification which follows, are obtained by the invention.
The present invention is based on using a naturally occuring unsaturated compound as a starting material for the synthesis of cyclic olefins. More particularly, the present invention uses terpenes, a group of unsaturated hydrocarbon compounds, which can be obtained from plans by steam distillation or ether extraction. The cyclic olefins are obtained by subjecting the isolated terpenes or a mixture thereof to a two-step process, in which the terpene(s) is (are) first hydrochlorinated and subjected to isomerization and then the chloride derivative thus obtained is subjected to elimination of hydrogen chloride (dehydrochlorination) to form an unsaturated cyclic compound. This compound can be used as a monomer or comonomer in addition polymerizations using, e.g. Ziegler-Natta, metallocene or other single site coordination catalysts; or it can be subjected to ring-opening polymerizations using methathesis catalysts; or it can be subjected to a Diels-Alder reaction to form a multicyclic monomer. By the latter method a new compound, trimethyl-tetracyclododecene, can be synthetized.
In particular, the process for producing novel cyclic olefins includes a hydrochlorination of a terpene and elimination of hydrogen chloride to form an unsaturated cyclic compound.
The polymers according to the present invention are trimethyl-tetracyclododecene.
Considerable advantages can be obtained by means of the present invention. Thus, plastics can now be made from renewable sources. The monomers of the present invention can replace norbornene and tetracyclododene in many processes and for many applications. They can also be used in combination with norbornene, tetracyclododecene and/or other substituted norbornenes in order to modify the technical properties of polymers.
The various features of novelty which characterize the invention are pointed out with particularity in the claims appended to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects obtained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.